package com.base.cn.platform.os.common.utils.qrCode;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;

/**
 * @Description:
 * @Author: Mr.Yang
 * @Date: Created in 15:31 2020/7/29 0029
 */
public class QrCodeUtil {

    public void QrExamPaperCode(String url, String paperName, HttpServletResponse response){
        try {
            Map<EncodeHintType, String> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            BitMatrix bitMatrix = new MultiFormatWriter().encode(url, BarcodeFormat.QR_CODE, 400, 400, hints);
            //清空输出流
            response.reset();
            //取得输出流
            OutputStream os = response.getOutputStream();
            response.setHeader("Content-Disposition", "attachment; filename="+paperName);
            MatrixToImageWriter.writeToStream(bitMatrix, "png", os);
            os.flush();
            //关闭输出流
            os.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /*public static void main(String[] args) {
        String url = "http://baidu.com";
        String path = "";
        String fileName = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()) + ".jpg";
        createQrCode(url, path, fileName);
    }*/

    public BitMatrix createQrCode(String url, String path, String fileName, String adminPath) {
        try {
            Map<EncodeHintType, String> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            BitMatrix bitMatrix = new MultiFormatWriter().encode(url, BarcodeFormat.QR_CODE, 400, 400, hints);
            return bitMatrix;

        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }

    static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, stream)) {
            throw new IOException("Could not write an image of format " + format);
        }
    }

    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;

    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
            }
        }
        return image;
    }
}
